My research involves examining the morphology of extant and extinct vertebrates, with a focus on the mammalian order Carnivora, to investigate how these animals co-exist, evolve and adapt to biotic and environmental change. I am interested in functional adaptations as tools for examining species ecological interactions in the past and present to make predictions for future generations of species. To answer these functional questions I use a morphometric approach which involves a combination of techniques including geometric morphometrics, radiographs, CT scans, and linear measurements. I am also interested in paleontological fieldwork and have participated in field work from sites across the U.S. from Florida to Wyoming.

Current Projects

With funding from National Geographic and my home institution, Des Moines University, we held our inaugural field season for this unique site from July 27 through August 9, 2014. The first field season was a success! We found a wide array of ice age mammal fossils and many many microfaunal fossils. This past year I have also received NSF funding for this project to continue for the next several years. This project is in conjunction with Co-PI Alan Cooper of the University of Adelaide and a large group of researchers from all over the U.S. We re-opened this exceptional site with the goal of investigating causes of the megafaunal extinction and paleoecological responses to climate change at the end of the Pleistocene. NTC gives us the opportunity to track genetic changes through a long period of time that spans the pre- to post-extinction events. A key strength of our approach is to bring a broad range of scientific methods and researchers together so that the same materials are analyzed using morphological, biogeochemical, and genetic techniques. This synergistic approach will establish a new standard for the analysis of recent paleontological material and promises to produce a far more resolved picture of paleoecological change than has previously been possible. Using ancient DNA, accelerated mass spectrometry (AMS) radiocarbon dates, ash-layer dating, stable isotope analyses, and results from previous studies of NTC we will correlate the timing of the extinction with climate records and genetic variation in species found at this locality. Here, we investigate the questions: Was the Pleistocene extinction event preceded by, or concurrent with a large loss of genetic variation? Do mammal species that did not go extinct exhibit similar genetic changes? Can population metastructure be detected through time, and how is this influenced by climate?

I recently had a paper come out related to this project on the wolves of Natural Trap Cave and their connection to Alaska! See my paper section for more information.

The field seasons in 2015 and 2016 have yielded excellent data, and now we are in the process of analyzing this data and preparing it for publication. We plan to have one more field season in 2017. Please email me if you have any questions about our fieldwork or future field seasons.

Radiocarbon dating and the extinction events at Rancho La Brea

Along with collaborators Robin O’Keefe from Marshall University, Wendy Binder from Loyola Marymount University, and Larisa DeSantis from Vanderbilt University I am involved
in a project at Rancho La Brea that will examine the timing and causes of the
mass extinction event as it happened at this locality. We are examining changes through time and in relationship to climate in the mammalian fauna from
Rancho La Brea. We are also hoping to extensively radiocarbon date the pits at Rancho La Brea so we can pinpoint the timing of important ecological events. This project is in conjunction with the AMS lab at UC Irvine and John Southon. We hope to answer the questions: What is the timing of the
extinction event at Rancho La Brea? Was climate driving size change at Rancho La Brea? Were the "tough times" correlated with a specific climate or environmental change?